This invention relates to a storage system, in particular, management of data whose preservation period is determined.
Among data stored in a storage system, there is data whose preservation for a certain period of time is obligated. Such data is, for instance, audit target data in a specific category of business.
There is a method with which a WORM (Write Once Read Many) attribute, in other words, an update prohibition attribute is given to such data at the time of storage, thereby proving that the data determined once is not erased or tampered and ensuring the correctness of the data.
In general, the WORM is property possessed by write-once optical disks and the like (CD-Rs, for instance). Therefore, by storing data on such write-once media, the WORM attribute is realized with ease.
Aside from this, from the viewpoint of performance and the like, a method is also proposed with which the WORM is realized in a storage system comprising a magnetic disk.
In JP 07-13705 A, a method is disclosed with which overwriting of data on a disk is prevented by providing a writing prohibition flag or the like on the disk.